SPECIAL TO THE STAR
In the early 1990s, George Bush Senior led the U.S. into war with Iraq's Saddam Hussein. "Operation Desert Storm" became the first war to be televised "live." Amid the images of explosions and soldiers and tanks covered in desert camouflage, the war also shed light on the Stealth jet fighter. Though it had been in use by the military since the early 1970s, for the first time it registered in the popular consciousness that this sleek jet fighter was virtually invisible to radar.
From H.G.Well's The Invisible Man to Star Wars, invisibility has been a holy grail of science fact and fiction
At the time, being invisible to radar was a concept that seemed to come straight from the movies, rather than an evening news report.
Fast forward to 2008, with American forces embedded in a much different Iraq and the talk about invisibility circulating at the Pentagon has gone beyond radar, and into the realm of sight. Or out of sight, quite literally.
Invisibility, once thought to be scientifically impossible and an outlandish concept promoted only in science fiction, is back, so to speak, on the radar.
In fact, one of the world's foremost physicists, Michio Kaku, has put his academic mind to some of science fiction's other concepts, such as teleportation and force fields, and is convinced that they, too, can become reality.
At Duke University, Kaku explains, researchers funded by the military were able in 2006 to render a microscopic object invisible to microwave radiation. Then, a few months ago, researchers at Cal Tech and in Germany achieved the same result with visible light.
"They were able to achieve invisibility to red and green light. Single colours of light can be bent in a way consistent with invisibility on a microscopic scale using nanotechnology," Kaku says.
This has huge potential on the battlefield. Imagine a tank being invisible to enemy forces. No wonder the Pentagon is bankrolling research in this field. "The next step is to do a large object at one light colour," Kaku says. "Within 10 years, we may be able to make an object completely invisible to one colour of light."
And that is only one of the seemingly outrageous accomplishments in the works that Kaku discusses in his new book, Physics of the Impossible.
While the chances of someone being teleported – as in the recent hit movie Jumper – is highly unlikely, Kaku points out that teleportation of an inorganic molecule has already been achieved.
And how about the fact that, while time travel poses philosophical questions that can twist your mind like trying to squeeze water out of a soaking wet towel, on principle it does not violate the known laws of physics.
In The Physics of the Impossible, Kaku discusses phasers, force fields, teleportation and time travel. While Kaku is a fan of science fiction, his work is nothing of the sort. His conclusions are measured probabilities based on the facts.
In the introduction of the book, he warns against ruling out great possibilities because "in my own short lifetime, I have seen the seemingly impossible become established fact over and over again."
Commenting on his book, which was published in March, Kaku says: "We are taking ideas that are usually the property of science fiction and we are looking at them with a very serious analysis with the most recent advances in physics."
"Science is doubling every 10 years – it's almost too much information to print. As a result, the public is really quite unaware of the breakthroughs that we are looking forward to over the next few decades."
How is it possible to make something invisible?
As Kaku himself writes in this month's edition of Natural History, a beam of light bends at a particular angle when it enters a given substance, such as glass, and then keeps going in a straight line. But what if you could control that angle at will, so that, for instance, it changed continuously from point to point in the glass?
"If a beam of light could create its own path – slithering around an object's atoms like a snake – and exit the material along the same line it entered, then the object could be invisible," Kaku writes.
Researchers at Duke University in Durham, North Carolina and Imperial College in London were able to achieve that with microwaves in 2006.
Kaku believes that by using metamaterials, a substance with optical properties not found in nature, scientists will be able to eventually render subjects invisible.
Another seemingly impossible idea that Kaku deals with is travel outside of our solar system. While the concept of bringing a mega-size starship with hundreds of people aboard to another star is not likely, he says NASA is making advances toward sending billions of self-reproducing nanosized exploration vessels throughout the galaxy.
Though many of these proposals are projected in the distant future, there are some more immediate changes ahead.
A few weeks ago, Kaku was invited by Microsoft to speak before an internal audience of about 4,000 of the company's top engineers. He was there to explain his contention that the age of computers as we know them, with transistors imprinted by ultraviolet radiation onto silicon chips, will soon reach a peak. "We are coming to the point where they will not be able to go faster. We have to go to the next generation," he explains.
Some of the changes that excite Kaku are the possibilities of computers carrying information through light instead of electricity, or computers functioning on DNA molecules.
Another reality that may change our view of the possible is the question of extraterrestrial life.
"It's almost a certainty; microbial life for sure," Kaku explains.
"The odds are that there are civilizations much more advanced than us. We can count 100 billion stars in our galaxy and 100 billion galaxies in the visible universe. That's 100 billion squared for the number of stars in the visible universe. The probability that one of these stars has a planet that will have life more intelligent than us, I think, is 100 per cent."
This marriage of science fact and science fiction, while exciting, Michio concedes, is nothing new. Instead, Michio points out that they are interrelated traditions.
"The idea of warping in space comes from Einstein not Star Trek, and the invention the atomic bomb was predicted almost to the date in an H.G Wells novel."